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281.
基于对重庆市国省干线公路灾害特性、类型、空间分布、原因机理进行研究,得出重庆市国省干线公路灾害发育,并且具有十分明显的分区发育特征的结论,分析了灾害发生的诱因,提出了充分重视地质勘查工作,合理规划和控制人类工程活动,严格控制工程质量,强化灾害分布预测,改进灾害时间预报的防治措施. 相似文献
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283.
An intermodal transportation terminal is a facility that provides commuters with easy transfer between transit modes and providers such as buses, light rail, subway, taxis, airport shuttles, and commuter rail. The probability of a passenger transferring from one mode to another and the estimation of total transfer demand are of great importance to both practitioners and researchers when determining optimal design alternatives as well as the best control and management policies for daily operation of the terminal. This article presents a study that uses an entropy-based optimization approach to estimate the transfer demands between the available transportation modes in an intermodal transportation terminal. The development and calibration of the entropy model is presented in the first part of the article, which is followed by a case study of the SiHui Intermodal Terminal in Beijing, China. 相似文献
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The container cargo proportion of total maritime transport increased from 3% in 1980 to 16% in 2011. The largest Brazilian port, the port of Santos, is the 42nd largest container port in the world. However, Santos’ performance indicators are much lower than those of the world’s largest ports, so comparisons with them are difficult. This article focuses on the Brazilian container terminals that handled containers in 2009 and compares port competitiveness. This study classified seventeen Brazilian container terminals into three distinct groups based on the following competitiveness criteria: number of containers handled, berth length, number of berths, terminal tariffs (in US$), berth depth, rate of medium consignment (in containers/ship), medium board (containers/hour), average waiting time for mooring (in hours/ship), and average waiting time for load or unload cargo (in hours/ship). This classification used a hierarchical cluster analysis. The classification shows that the terminal of Tecon in the port of Santos has the best performance of all, while small terminals (<150,000 container units) are the worst performing terminals in Brazil. 相似文献
286.
李建 《交通部上海船舶运输科学研究所学报》2008,31(1):35-44
研究了基于先进的精简指令集处理器(Advanced RISC Machines,缩写ARM)的嵌入式显示终端的应用开发,运用先进的ARM微处理器核心技术、嵌入式软件技术、嵌入式图形用户界面技术、串行通信技术、信息的存储和管理技术等,完成了以S3C44BOX处理器为核心的硬件平台的设计,并在此基础上完成了μC/OS-II嵌入式操作系统的移植,以及系统软件主要功能模块的实现。研制出能够满足船舶能量管理系统(Power Manage System,缩写PMS)中实际需要的嵌入式显示终端。 相似文献
287.
《铁道标准设计通讯》2013,(6)
位于中西部山区的高速铁路需修建大量的桥隧工程,造成桥台(梁)伸入隧道内布置,隧道洞口段往往为土质地层或基岩风化层,地质条件比较差,桥隧相连段隧道断面大,结构受力复杂,设计、施工难度很大,处理不好,容易留下安全隐患。以西成客运专线工程设计为实例,采用工程类比与理论计算相结合的方法,对桥隧相连段的尺寸拟定、结构设计、排水设计方案等主要技术难点进行研究,成功解决了桥隧相连段的设计难题。研究结论:(1)隧道净空尺寸除满足建筑限界外,必需考虑桥台、梁的结构尺寸、检修高度、设备布置等综合因素;(2)桥隧相连段断面大,结构措施宁强勿弱、安全可靠;(3)隧道低洞口端要设置汇水井、转向排水管、引排管等设施,解决排水问题。 相似文献
288.
研究目的:遵循"以人为本、服务运输、强本简末、系统优化、着眼发展"的设计理念,结合合肥枢纽的现状,统筹考虑枢纽在建项目、拟建项目及规划项目,系统研究确定推荐方案及重大比选方案,为枢纽总图研究及设计积累经验。研究结论:随着合肥南站的建设,枢纽形成了两大客站的格局,以此为前提,研究了集中引入合肥南站方案、商阜杭引入合肥站方案、商阜杭引入合肥南站方案和商阜杭新建客站方案四大系列方案。经研究比选,集中引入合肥南站方案在运输组织、旅客出行、点线能力协调等方面具有明显的优势,但合肥南站已经开工建设,对其进行调整存在不确定性,因此建议下阶段根据合肥南站工程调整的可能性对集中引入合肥南站方案、商阜杭引入合肥站方案进一步深入研究比选。 相似文献
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The link transmission model (LTM) has great potential for simulating traffic flow in large-scale networks since it is much more efficient and accurate than the Cell Transmission Model (CTM). However, there lack general continuous formulations of LTM, and there has been no systematic study on its analytical properties such as stationary states and stability of network traffic flow. In this study we attempt to fill the gaps. First we apply the Hopf–Lax formula to derive Newell’s simplified kinematic wave model with given boundary cumulative flows and the triangular fundamental diagram. We then apply the Hopf–Lax formula to define link demand and supply functions, as well as link queue and vacancy functions, and present two continuous formulations of LTM, by incorporating boundary demands and supplies as well as invariant macroscopic junction models. With continuous LTM, we define and solve the stationary states in a road network. We also apply LTM to directly derive a Poincaré map to analyze the stability of stationary states in a diverge-merge network. Finally we present an example to show that LTM is not well-defined with non-invariant junction models. We can see that Newell’s model and continuous LTM complement each other and provide an alternative formulation of the network kinematic wave theory. This study paves the way for further extensions, analyses, and applications of LTM in the future. 相似文献